The present invention relates to a blow molded, plastic container having an inclined or angled mouth and neck portion, and a method and apparatus for preparing same.
Blow molded plastic containers, such as those made from polyethylene terephthalate, are widely used for many applications, such as, for example, as containers for drinks and cleaning products. These containers customarily have a straight mouth and neck portion, that is, a mouth and neck portion that are coaxial with the body portion of the container.
The preparation of these containers generally involves preparing a preform or parison with a mouth and neck portion that are coaxial with the preform body portion, holding the preform in a blow mold with the preform mouth and neck portion held coaxial with the preform body portion, and forming the desired container in the shape of the blow mold by stretching and blow molding.
For many applications it is desirable to prepare such a container with a mouth and neck portion at an angle to the body portion of the container. However, it is difficult to prepare such an angled mouth and neck portion container by conventional blow molding techniques. For example, such techniques may involve expensive and inconvenient multistage operations where an injected preform is clamped, stretched and blown in the mold at one station and a blow pin is inserted into the mold for blowing and/or compression molding at another station and the neck is bent at a subsequent station or in a subsequent stage of operation. Techniques such as this increase the cost of the container and complicate processing.
Alternatively, a conventional type apparatus cannot be satisfactorily used to mold a container with an angled mouth and neck portion since to do so would require the mold cavity to be aligned so that the desired angular neck is appropriately aligned with the blow pin. Significant processing problems result thereby, as well as problems with the resultant container.
Accordingly, it is a principal objective of the present invention to provide a new and improved method and apparatus for obtaining a blow molded, plastic container with an angled or inclined neck and mouth portion.
It is a still further objective of the present invention to provide an improved blow molded, plastic container with an angled or inclined neck and mouth portion.
It is an additional objective of the present invention to provide a method and apparatus as aforesaid which is easy and expeditious to use on a commercial scale, and which simply and conveniently provides improved containers as aforesaid.
Further objects and advantages of the present invention will appear hereinbelow.
In accordance with the present invention it has now been found that the foregoing objects and advantages are readily obtained.
The present invention provides a method of forming a blow molded plastic container, preferably polyethylene terephthalate although other plastic materials can be readily used, said container having a mouth and neck portion thereof which are inclined or angled with respect to the body portion of the container. The method comprises:
providing a straight, cylindrical plastic parison or preform having a closed base, straight body portion extending therefrom, straight neck portion extending from the body portion, and an open mouth;
placing said preform in a blow mold having the desired container configuration and clamping or holding the preform in place in the blow mold;
introducing a stretch rod into the preform and extending said preform substantially to the base of the blow mold with said stretch rod to provide an extended preform;
providing a blow nozzle with an angled face corresponding to the desired angle of the mouth and neck portion of the container, generally less than 45xc2x0 with respect to the longitudinal axis of the container;
engaging said angled face of the blow nozzle with the open mouth of the preform and bending the open mouth and neck portion of the preform by the angled face of the blow nozzle to correspond to the angle of the face of the blow nozzle; and
introducing high pressure air into the extended bent neck preform from the blow nozzle to stretch the extended bent neck preform into conformity with the shape of the blow mold and to provide a biaxially oriented container having an angled mouth and neck portion.
The apparatus of the present invention comprises:
a blow mold having the desired container configuration for holding in place therein a straight, cylindrical plastic parison or preform having a closed base, straight body portion extending from the base, straight neck portion extending from the body portion, and open mouth;
a stretch rod associated with the blow mold for introduction to the preform operative to extend the preform substantially to the base of the blow mold and provide an extended preform;
a blow nozzle associated with the blow mold having an angled face corresponding to the desired angle of the mouth and neck portion of the container, generally less than 45xc2x0 with respect to the longitudinal axis of the container;
wherein said angled face of the blow nozzle is operative to engage the open mouth of the preform and bend the open mouth and neck portion of the preform to correspond to the angle of the face of the blow nozzle, and wherein said blow nozzle is operative to introduce high pressure air into the angled mouth and neck of the extended preform to stretch the extended preform into conformity with the shape of the blow mold and to provide a biaxially oriented container having an angled mouth and neck portion.
The container of the present invention comprises:
a biaxially oriented, blow molded container prepared from a straight, cylindrical preform or parison, said container having a closed base, a body portion extending from the closed base, a neck portion extending from the body portion, an open mouth, and a longitudinal axis; wherein said body portion has an upper portion and a lower portion, and in cross section one side of the upper body portion includes a gradual, continuous, curved configuration extending to the angled neck, and the opposed side of the upper portion has a stepped configuration extending to the angled neck.
The container of the present invention is desirably polyethylene terephthalate and may if desired include an amount of post consumer resin (PCR), for example, up to about 75%. Also, if desired the container may be of a multilayer construction. Desirably, the container may have a threaded neck and an outwardly extending flange in the neck portion beneath the threaded portion.
Other features and advantages of the present invention will appear hereinbelow.